The writing process for the majority of Metallicaâs albums have followed the same process. A large slew of guitar riffs written primarily by James Hetfield, sometimes Kirk Hammett, and rarely the bandâs bass player, (that now being bass virtuoso Robert Trujillo) are reviewed and selected.
1 Delhi is most polluted city in the world in PM2.5 concentrations. 2  Half of the top 20 most polluted cities were in India, according to data.  PM2.5 is considered most harmful to health.
Linfen, China. Linfen, China is the most polluted city on earth. According to The Daily Green, if one puts laundry out to dry, it will turn black before finishing drying. Located in China's coal belt, spending one day in Linfen is equivalent to smoking three packs of cigarettes.